The Method Dynamics Flash Drive Flash Hider is machined from 17-4 PH H900 stainless steel and is compatible with all Plan B muzzle devices and mounts. NOTE: This muzzle device requires the use of suppressor grease on all Plan B muzzle device to Plan B/HUB suppressor adapters to prevent carbon lock seizing. Failure to use grease will void limited lifetime warranty. Product Specifications Model: Plan B Flash Drive 3-Prong Flash Hider Caliber: Designed with a .375 Bore, making it compatible with .223/5.56mm, 6.5mm, and up to .30 caliber projectiles. Type: 3-Prong / suppressor mount. Muzzle Thread: 1/2"-28 TPI Material: 17-4 PH H900 Stainless Steel Finish: Heat Treat (indicated by "HT" or "-H" in the part number), providing a natural straw-to-bronze coloration from the hardening process. Length: Approximately 1.7 to 2.2 inches Width: Standard profiles typically measure approximately 0.850" to 0.900" at the widest point to interface with Plan B adapters. Weight: Listed at approximately 0.13 lbs (shipping weight), with the device itself typically weighing between 2.0 and 2.5 oz.